This invention relates to a portable caulking guns and more particularly to a new and improved caulking gun that employs a disposable cartridge, a new and improved disposable caulking cartridge; and a new combination of gun and cartridge.
One of the problems with the dispensing of caulking compounds is that they are thixotropic in nature and are generally extruded from a caulking cartridge with the aid of a caulking gun through the nozzle of the cartridge under substantial pressure. Caulking compounds are often spoken of as viscous in nature, however, because of additives, the additional property of resistance to flow must be considered. Thixotropic is the resistance to flow and sag. Additives are mixed into some caulking compound to provide this property of resistance to prevent their flow and sag after application, however, such property also contributes to a problem of interfering with the free flow of the caulking material through the caulking cartridge and nozzle. In the case of caulking compounds for use in the construction industry, the additives added are those such as fumed silica, Thixatrol.RTM., asbestos and Thixatrol-R.RTM.. These additives make the caulking compound desirable for use in caulking overhead seams or vertical spaces between joining elements since there is no propensity for the caulking seam to flow or sag from the site of its application. Due to the nature of the thixotropic type caulking material which is plastic and somewhat elastic, there is considerable compressing of the material under the actuating pressure, and when the operator interrupts the operation of dispensing a bead of the caulking compound, the caulking material continues to flow and ooze out of the caulking gun because of the compression, which action is wasteful of the material, untidy and very time consuming as where such sticky caulking material must be cleaned up.
Where only a single tube is used, there may be no great problem, but on construction sites where extensive caulking must be done, the problem of using thixotropic compounds where continued flow occurs presents a serious problem.
A further consideration that must be recognized is the type of caulking gun used or is being referred to. The first type to be considered is a B-D gun or a bulk dispensing gun which is a complete unit unto itself, containing a closed cylindrical chamber or shell with nozzle and actuating means. The second type of caulking gun used is one that has an open framed supporting structure with an actuating mechanism plus a separate disposable cartridge that has its own nozzle. The latter type of open framed cartridge gun (C-gun) is essentially a two separate unit type of caulking gun, with the cartridge and its nozzle being the second separate and disposable element of the gun.
In the case of the C-gun or cartridge gun, the opening of the nozzle in the cartridge is not consistent in its diameter opening even though a cut on the nozzle is made at the same reference point (i.e., as one inch from the tip) because the nature of the materials used allows an inconsistent growth in size of the product nozzle after release from the mold. A further problem of the C-gun is the clean up and health hazard created by the numerous continuing flow after release of the actuating mechanism. Hazardous solvents must be used for clean up of the work affected area and the operator's skin. In both the C-gun and the B-D gun, changing colors is difficult and particularly time consuming in the case of the bulk disposing (B-D) gun. Some type of tool must be used in the case of the cartridge type gun to puncture the cartridge seal to initiate the flow of the caulking material. Applicant's invention requires no tool to puncture a seal to effect flow, thereby eliminating the need to carry such tool which in all instances, has the caulking compound on it for exposure to contact by the operator. In applicant's invention, no human contact with the caulking material or the adhesive material is required. The adhesive material referred to is that used on the foil to bond it to the metal end cap of the cartridge prior to the affixing of the nozzle to the cartridge. In the case of the bulk dispensing gun, the loading generally relies on the use of vacuum to load the cylindrical shell whereas the invention provides for a faster means to load and use, which is particularly advantageously in view of the thixotropic and viscous properties of the caulking compound. Where the B-D gun uses a transfer device, such as a pressure driven ram to the gunning head, additional heavy duty equipment must be employed, taking up space, which is in sharp contrast to the invention that employs disposable caulking compound containers.
The present invention provides a new and improved dispensing gun, cartridge and system, which more accurately controls the dispensing of the caulking material, allowing for flow interruption without the need for cleanup. In addition, the caulking disposable cartridge of the present invention is useable with the cartridge, caulking guns having a new and improved construction that facilitates the even flow of the caulking material and prevents the build up of pressure within the cartridge itself.